1. Technical Field of the Invention
The present invention relates to a color filter substrate having a reflecting layer, a method of fabricating a color filter substrate, a liquid crystal device, a method of forming a liquid crystal device, and an electronic apparatus.
2. Description of the Related Art
In a liquid crystal device, a liquid crystal is interposed between a pair of substrates which are opposed to each other, and light passing through the liquid crystal is modulated in response to the alignment state of the liquid crystal, and thus a display is performed. As the display mode of such a liquid crystal display device, a reflective mode, a transmissive mode, and a transflective mode having characteristics of both modes are known.
In a transmissive liquid crystal device shown in FIG. 11, transparent electrodes 280 composed of ITO (indium tin oxide) or the like are disposed on each of the opposing surfaces of a substrate 220 and a counter substrate 240, and a color filter layer 320 is interposed between the substrate 220 and the transparent electrode 280 on the side of the substrate 220. By controlling the alignment state of liquid crystal molecules in a liquid crystal 260, light emitted from a light source (backlight) 400 provided at the exterior of the substrate 220 is modulated by the liquid crystal 260 and is transmitted to the counter substrate 240 side, and thus a color image is displayed.
In a reflective liquid crystal device, for example, disclosed in Japanese Unexamined Patent Application Publication No. 6-230364, as shown in FIG. 12, a color filter layer 320 is formed under a transparent electrode on the side of a substrate 220, and a light-reflecting metal film (reflecting layer) 300 is provided between the color filter layer 320 and the substrate 220. When external light 420, which enters from the side of a counter substrate 240, and which is transmitted through a liquid crystal 260, is reflected from the metal film 300 back to the incident side, a color image is displayed by controlling the alignment state of liquid crystal molecules of the liquid crystal 260. In such a reflective display device, even if a light source, such as a backlight, is not provided, display can be performed using ambient light, such as a fluorescent lamp or natural light, which is advantageous in view of power consumption, and thus it is widely used for mobile display devices, etc.
The color filter layer 320 for enabling the liquid crystal device to perform color display comprises a color filter layer of any one of three primary colors, i.e., blue, green, and red, and is disposed corresponding to each pixel (i.e., a dot which is referred to as a sub-pixel).
The color filter layer is generally formed by a dyeing method or a dye dispersion method. In the dyeing method, a polymeric material is applied to a substrate, patterning is performed by photolithography, followed by immersion in a dyeing bath to form a color filter layer of each color. In the dye dispersion method, a photosensitive resin in which a predetermined dye is dispersed so as to have any one of the primary colors is applied to a substrate, and patterning is performed to form a color filter layer of each color.
However, in the reflective liquid crystal device in which a color filter layer must be formed on a metal film, separations and defects of the color filter layer may occur due to insufficient adhesion between the metal film and the color filter layer. The reason for this is believed to be that since the color filter layer uses the polymeric material or the resin as a base, affinity for the metal is decreased.
Additionally, as a technique for improving adhesion between a metal and a resin, etc., the application of a primer on the surface of the metal has been known. However, if this technique is used for forming a color filter substrate, production efficiency is decreased due to an additional process step, and also, image quality may be degraded due to the primer.
It is an object of the present invention to provide a color filter substrate, a method of fabricating a color filter substrate, a liquid crystal device, a method of fabricating a liquid crystal device, and an electronic apparatus, in which the problems described above are overcome and adhesion between a reflecting layer and color filter layers can be improved without increasing the number of steps in the fabrication process.
In accordance with the present invention, in a color filter substrate having a plurality of pixels includes a reflecting layer composed of a metal film formed on a substrate, and any one of a blue color filter layer, a green color filter layer, and a red color filter layer formed on the reflecting layer at a position corresponding to each pixel. A metal complex of phthalocyanine is applied to the surface of the reflecting layer at the interface with the color filter layer.
In such a configuration, since the metal complex of phthalocyanine having superior adhesion with the reflecting layer and the color filter layer is applied to the surface of the reflecting layer and each color filter layer is formed thereon, the adhesion between the reflecting layer and the color filter layer can be improved.
Preferably, the blue color filter layer contains a dye composed of the metal complex of phthalocyanine.
Preferably, a shading film having a layered structure comprising the color filter layers of the individual colors is disposed on the surface of the reflecting layer between the individual pixels, a substrate-side layer in the shading film is the blue color filter layer, and the blue color filter layer contains a dye composed of the metal complex of phthalocyanine.
Preferably, an outermost layer in the shading film is the red color filter layer.
Preferably, a black shading film is disposed on the surface of the reflecting layer between the individual pixels, and the black shading film contains a dye composed of the metal complex of phthalocyanine.
Preferably, the metal complex of phthalocyanine is copper phthalocyanine.
Preferably, the reflecting layer at the position corresponding to each pixel is provided with a window for transmitting light.
In accordance with the present invention, a method of fabricating a color filter substrate having a plurality of discrete pixels, includes a first step of forming a blue color filter layer-forming film on a reflecting layer composed of a metal film formed on a substrate; a second step of forming a blue color filter layer on the reflecting layer at positions corresponding to predetermined pixels by patterning the blue color filter layer-forming film; a third step of forming a green or red color filter layer-forming film on the blue color filter layer and on the reflecting layer exposed in the second step; a fourth step of forming a green or red color filter layer on the reflecting layer exposed in the second step at positions corresponding to predetermined pixels by patterning the green or red color filter layer-forming film; a fifth step of forming a color filter layer-forming film of the color not selected in the third step on the blue color filter layer, on the green or red color filter layer, and on the reflecting layer exposed in the fourth step; and a sixth step of forming a color filter layer of the color not selected in the third step on the reflecting layer exposed in the fourth step at positions corresponding to predetermined pixels by patterning the color filter layer-forming film formed in the fifth step. The blue color filter layer contains a dye composed of a metal complex of phthalocyanine.
In such a configuration, when the blue color filter layer is formed on the reflecting layer and the blue color filter layer is then patterned, the metal complex of phthalocyanine having superior adhesion with the individual color filter layers is applied to the surface of the reflecting layer. Since the individual color filters are formed thereon, the adhesion between the reflecting layer and the individual color filter layers can be improved.
Preferably, in the second step, the blue color filter layer is formed on the reflecting layer between the individual pixels, in the fourth step, the green or red color filter layer is formed on the blue color filter layer between the individual pixels, and in the sixth step, the color filter layer of the color not selected in the third step is formed on the green or red color filter layer between the individual pixels, and thus a shading film having a layered structure comprising the color filter layers of the individual colors is formed, a substrate-side layer in the shading film being the blue color filter layer.
In such a configuration, since the blue color filter layer is formed first on the reflecting layer, the metal complex of phthalocyanine is applied to the surface of the reflecting layer, and since the shading film is formed by combining the individual color filter layers, a step for forming the shading film is not required, thus improving production efficiency.
Preferably, in the third step, the green color filter layer-forming film is formed.
In this way, since the red color filter layer is formed last among the individual color filter layers, it is possible to prevent residues from remaining when the red color filter layer is patterned, and therefore, the tone of the green color filter layer formed thereon is not impaired.
In accordance with the present invention, a method of fabricating a color filter substrate includes the steps of forming a black shading film-forming film containing a dye composed of a metal complex of phthalocyanine on a reflecting layer composed of a metal film formed on a substrate; forming a black shading film on the reflecting layer between the individual pixels by patterning the shading film-forming film; and forming any one of a blue color filter layer, a green color filter layer, and a red color filter layer on the reflecting layer at the position corresponding to each pixel before or after the black shading film-forming film is formed.
In accordance with the present invention, a liquid crystal device includes the color filter substrate described above and a counter substrate disposed opposite to the color filter substrate with a liquid crystal therebetween.
In accordance with the present invention, a method of fabricating a liquid crystal device includes the method of fabricating the color filter substrate described above.
In accordance with the present invention, an electronic apparatus includes the liquid crystal device described above.